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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-07 23:54:13 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-07 23:54:13 +0300 |
commit | 11777ee8b04acab07c96959e9c6ac6a1603d0958 (patch) | |
tree | 52a7bf02de5076afd4bac1b351bdd2f7c59ff847 /drivers/i2c/muxes/i2c-mux-pca954x.c | |
parent | ed39ba0ec1156407040e7509cb19299b5dda3815 (diff) | |
parent | b49f8e0e7bd17b968129790e40f9e2566f4f95ec (diff) | |
download | linux-11777ee8b04acab07c96959e9c6ac6a1603d0958.tar.xz |
Merge branch 'i2c/for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"i2c core:
- huge improvements and refactorizations of the Linux I2C
documentation (lots of thanks to Luca for doing it and Jean for the
careful review)
- subsystem wide API conversion to i2c_new_client_device()
- remove obsolete parport-light driver
- smaller core updates (removal of 'extern', enabling more compile
testing, use more helper macros)
- and quite a bunch of driver updates (new IDs, simplifications,
better PM, support of atomic transfers and other improvements)
i2c-mux:
- The main feature is the idle-state rework of the pca954x driver
from Biwen Li
at24 driver:
- minor maintenance: update the license tag, sort headers
- move support for the write-protect pin into nvmem core
- add a reference to the new wp-gpios property in nvmem to at25
bindings
- add support for regulator and pm_runtime control"
* 'i2c/for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (91 commits)
i2c: cros-ec-tunnel: Fix ACPI identifier
i2c: cros-ec-tunnel: Fix slave device enumeration
i2c: stm32f7: add PM_SLEEP suspend/resume support
i2c: cadence: Fix wording in i2c-cadence driver
i2c: cadence: Fix power management order of operations
i2c: cadence: Fix error printing in case of defer
i2c: cadence: Handle transfer_size rollover
i2c: i801: Add support for Intel Comet Lake PCH-V
docs: i2c: writing-clients: properly name the stop condition
docs: i2c: i2c-protocol: use same wording as smbus-protocol
docs: i2c: rename sections so the overall picture is clearer
docs: i2c: old-module-parameters: use monospace instead of ""
docs: i2c: old-module-parameters: clarify this is for obsolete kernels
docs: i2c: old-module-parameters: fix internal hyperlink
docs: i2c: instantiating-devices: use monospace for sysfs attributes
docs: i2c: instantiating-devices: rearrange static instatiation
docs: i2c: instantiating-devices: fix internal hyperlink
docs: i2c: smbus-protocol: improve I2C Block transactions description
docs: i2c: smbus-protocol: fix punctuation
docs: i2c: smbus-protocol: fix typo
...
Diffstat (limited to 'drivers/i2c/muxes/i2c-mux-pca954x.c')
-rw-r--r-- | drivers/i2c/muxes/i2c-mux-pca954x.c | 69 |
1 files changed, 46 insertions, 23 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 923aa3a5a3dc..a0d926ae3f86 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -86,7 +86,7 @@ struct pca954x { u8 last_chan; /* last register value */ /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ - s8 idle_state; + s32 idle_state; struct i2c_client *client; @@ -229,20 +229,23 @@ static int pca954x_reg_write(struct i2c_adapter *adap, I2C_SMBUS_BYTE, &dummy); } +static u8 pca954x_regval(struct pca954x *data, u8 chan) +{ + /* We make switches look like muxes, not sure how to be smarter. */ + if (data->chip->muxtype == pca954x_ismux) + return chan | data->chip->enable; + else + return 1 << chan; +} + static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - const struct chip_desc *chip = data->chip; u8 regval; int ret = 0; - /* we make switches look like muxes, not sure how to be smarter */ - if (chip->muxtype == pca954x_ismux) - regval = chan | chip->enable; - else - regval = 1 << chan; - + regval = pca954x_regval(data, chan); /* Only select the channel if its different from the last channel */ if (data->last_chan != regval) { ret = pca954x_reg_write(muxc->parent, client, regval); @@ -256,7 +259,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - s8 idle_state; + s32 idle_state; idle_state = READ_ONCE(data->idle_state); if (idle_state >= 0) @@ -402,6 +405,22 @@ static void pca954x_cleanup(struct i2c_mux_core *muxc) i2c_mux_del_adapters(muxc); } +static int pca954x_init(struct i2c_client *client, struct pca954x *data) +{ + int ret; + + if (data->idle_state >= 0) + data->last_chan = pca954x_regval(data, data->idle_state); + else + data->last_chan = 0; /* Disconnect multiplexer */ + + ret = i2c_smbus_write_byte(client, data->last_chan); + if (ret < 0) + data->last_chan = 0; + + return ret; +} + /* * I2C init/probing/exit functions */ @@ -411,7 +430,6 @@ static int pca954x_probe(struct i2c_client *client, struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; struct device_node *np = dev->of_node; - bool idle_disconnect_dt; struct gpio_desc *gpio; struct i2c_mux_core *muxc; struct pca954x *data; @@ -462,23 +480,24 @@ static int pca954x_probe(struct i2c_client *client, } } - /* Write the mux register at addr to verify + data->idle_state = MUX_IDLE_AS_IS; + if (of_property_read_u32(np, "idle-state", &data->idle_state)) { + if (np && of_property_read_bool(np, "i2c-mux-idle-disconnect")) + data->idle_state = MUX_IDLE_DISCONNECT; + } + + /* + * Write the mux register at addr to verify * that the mux is in fact present. This also - * initializes the mux to disconnected state. + * initializes the mux to a channel + * or disconnected state. */ - if (i2c_smbus_write_byte(client, 0) < 0) { + ret = pca954x_init(client, data); + if (ret < 0) { dev_warn(dev, "probe failed\n"); return -ENODEV; } - data->last_chan = 0; /* force the first selection */ - data->idle_state = MUX_IDLE_AS_IS; - - idle_disconnect_dt = np && - of_property_read_bool(np, "i2c-mux-idle-disconnect"); - if (idle_disconnect_dt) - data->idle_state = MUX_IDLE_DISCONNECT; - ret = pca954x_irq_setup(muxc); if (ret) goto fail_cleanup; @@ -530,9 +549,13 @@ static int pca954x_resume(struct device *dev) struct i2c_client *client = to_i2c_client(dev); struct i2c_mux_core *muxc = i2c_get_clientdata(client); struct pca954x *data = i2c_mux_priv(muxc); + int ret; - data->last_chan = 0; - return i2c_smbus_write_byte(client, 0); + ret = pca954x_init(client, data); + if (ret < 0) + dev_err(&client->dev, "failed to verify mux presence\n"); + + return ret; } #endif |